If you do not submit your trademark to the TMCH, you still have the normal procedures for brand protection: you can bring anyone that registered yourtrademark.tld to the court to claim your domain. Depending on the registry's policies, this claim will be accepted or rejected. This is not different from current disputes under .com or .nl for example.

The advantage of a TMCH registration is that you are actively notified if somebody registers yourtrademark.tld.